Abstract

Geographical distribution in Sardinia of different karyological biotypes of Dugesia (Schmidtea)polychroa and Dugesia (S.) mediterranea has been investigated.
On the whole, 4 biotypes of Dugesia (S.)Polychroa (A, C. D, and A pentaploid biotypes) and 2 biotypes of Dugesia (S.) mediterranea (G, and G triploid biotypes) have been recorded. The A pentaploid and G triploid biotypes were never found in Sardinia
before now.
We wish to underline i) the fìnding, in the Temo river, of 5 different biotypes: C, D, A pentaploid of Dugesia (S.) polychroa and G, G triploid of Dugesia (S.)mediterranea; ii) no biotypes of Dugesia (S.) polychroa or Dugesia (S.)mediterranea, up to date, have been found by us in the oriental catchment areas of Sardinia.